Web for fluid filled unit formation

Abstract

A web for the manufacture of fluid filled units with a novel machine and process is disclosed. The web includes an elongate heat sealable, flattened plastic tube comprised of face and back imperforate layers. The layers are imperforately joined together along spaced side edges. The layers include superposed longitudinal lines of weakness disposed generally transversely midway between the side edges. The web has longitudinally spaced, pairs of transverse seals. Each transverse seal extends from a respective side edge to an end near but spaced from the longitudinal lines of weakness. The transverse seal pairs include transverse lines of weakness extending from one side edge to the other generally centrally of each seal in a longitudinal direction. The side edges, transverse seals and lines of weakness together delineating two oppositely oriented strings of pouches with each pouch having three imperforate sides and a centrally located fill opening at its fourth side. The transverse lines of weakness are spaced slightly more than one half the circumference of a cylindrical fluid fill nozzle used to fill the pouches such that the web closely surrounds the nozzle during pouch fluid filling.

1. A web for the manufacture of fluid filled units comprising:
 an elongate heat sealable, flattened plastic face and back layers including imperforate sections; 
 the layers being imperforately joined together at a side edge by a selected one of a fold and a seal; 
 the layers being joined by longitudinally spaced transverse seals, each transverse seal extends from the side edge and terminates in a spaced relationship with a fill edge of the layers; 
 transverse lines of weakness extending from the side edge to the fill edge in a longitudinal direction of the seals that allow adjacent pouches to be separated; 
 the side edge and transverse seals and lines of weakness together delineating a string of pouches with each pouch having two imperforate sections, three imperforate sides and a centrally located fill opening at its fourth side; and, 
 the transverse lines of weakness being defined by spaced perforations extending through both layers with the perforations nearest to the fill edge of the layers being shorter in length than the lengths of other perforations that are spaced further from the fill edge and extend toward the side edge. 
 
     
     
       2. The web of  claim 1  wherein each of the shorter perforations are between and spaced from an associated transverse seal and the fill edge. 
     
     
       3. The web of  claim 1  wherein the layers are split during an inflation process to form the fill edge. 
     
     
       4. The web of  claim 1  wherein at least some of the transverse seals include a transverse line of weakness. 
     
     
       5. The web of  claim 4  wherein each transverse line of weakness longitudinally bisects the seal in which it is formed. 
     
     
       6. The web of  claim 1  wherein those of the transverse perforations that are elongate are closely spaced such that sides of successive pouches are lightly tacked together for facile separation following inflation and sealing. 
     
     
       7. The web of  claim 6  wherein each of the shorter perforations are between and spaced from an associated transverse seal and the fill edge. 
     
     
       8. A plastic web for the manufacture of fluid filled units comprising:
 an elongate flattened top and bottom layers; 
 the layers being longitudinally joined a side edge by a selected one of a fold and a seal; 
 longitudinally spaced transverse seals, the seals extending from the side edge toward but spaced from a fill edge of the layers; 
 a plurality of longitudinally spaced transverse lines of weakness extending substantially from the side edge to the fill edge; and 
 the transverse lines of weakness being perforations including relatively short perforations extending from the fill edge toward the side edge and longer perforations that extend from the short perforations toward the side edge. 
 
     
     
       9. The web of  claim 8  wherein there are spaced sets of large perforations with the sets respectively solely in an associated transverse seal. 
     
     
       10. The web of  claim 8  wherein those of the transverse perforations that are elongate are closely spaced such that sides of successive pouches are lightly tacked together for facile separation following inflation and sealing. 
     
     
       11. The web of  claim 8  wherein the layers apart from the said lines of weakness are imperforate. 
     
     
       12. The web of  claim 8  wherein the layers are split during an inflation process to form the fill edge. 
     
     
       13. The web of  claim 8  wherein at least some of the lines of weakness longitudinally bisect an associated transverse seal.